The present disclosure relates to asymmetric ansa-metallocene catalyst compounds that include at least one indenyl ligand substituted at the 3-position with a C.sub.3-C.sub.40 -branched alkyl, such as 1-methylethyl, 1-methylpropyl, 1-methylbutyl, 1-ethylbutyl, 1,3-dimethylbutyl, 1-methyl-1-ethylbutyl, 1,1-diethylbutyl, 1-propylpentyl, and the like. Catalyst systems prepared with the catalyst compounds, polymerization methods using such catalyst systems, and polyolefins made using the polymerization methods are also described.

The present invention provides a method for preparing a polyolefin having a broad molecular weight distribution. More specifically, the present invention provides a method for preparing a polyolefin having a broad molecular weight distribution and an ultra-high molecular weight in which an organometallic complex containing a specific TiAl complex structure is used as a molecular weight controller (i.e., molecular weight enhance) in the polymerization of an olefin monomer, thereby enabling both solution polymerization and slurry polymerization, particularly enabling the molecular weight distribution to be more readily and effectively controlled.

A mixed metallocene catalyst system can comprise at least one metallocene catalyst compound comprising a structure represented by formula (A) below and optionally at least one other metallocene catalyst compound having a structure represented by formula (B) below: ##STR00001##
A mixed metallocene catalyst system can additionally include a non-coordinating anion type activator comprising a supported alumoxane or aluminum alkyl, and optionally a scavenger. A process for making a polymeric product can comprise: contacting a C.sub.2-C.sub.22 alpha-olefin feed with the catalyst system to obtain a polymerization reaction mixture; and obtaining a polymer product from the polymerization reaction mixture. A polymer product can be made by the process.

The present disclosure relates to a method for preparing a supported hybrid metallocene catalyst, and the catalyst is prepared by supporting a first metallocene compound, supporting a cocatalyst by a separate-input method in which primarily adding a part at 100 C. to 150 C. and secondarily adding the rest at 5 C. to 40 C., and then supporting a second metallocene compound, thereby improving a supporting rate of the cocatalyst in the supported catalyst and maintaining high catalytic activity. Therefore, the present disclosure can effectively prepare a polyolefin with improved processability which exhibits increased molecular weight distribution while having high morphology (reduced fine powder), high bulk density and improved settling efficiency.

The present invention relates to an ethylene/alpha-olefin copolymer and, more particularly, to an ethylene/alpha-olefin copolymer that exhibits excellent environmental stress crack resistance by appropriately controlling the ratio of crystal structure domain and amorphous domain, and the like. The ethylene/alpha-olefin copolymer comprises an ethylene repeating unit and an alpha-olefin repeating unit, and has a crystal structure including a crystalline domain containing lamellar crystals and an amorphous domain containing a tie molecule that mediates bonding between the lamellar crystals. The lamellar crystal thickness (dc) of the ethylene/alpha-olefin copolymer as calculated from the result of Small Angle X-ray Scattering (SAXS) analysis is between 12.0 and 16.0 nm, the amorphous domain thickness (da) is between 4.0 and 5.3 nm, and the thickness ratio da/dc is between 0.3 and 0.4.

A metallocene catalyst compound can comprise a structure represented by formula (F-MC) below comprising a first cyclopentadienyl ring with carbon atoms directly connected with R.sup.1, R.sup.2, R.sup.4, and R.sup.5, and a second cyclopentadienyl ring with carbon atoms directly connected with R.sup.10, R.sup.11, R.sup.12, and R.sup.13, and a bridging group (BG) directly connecting the first and second cyclopentadienyl rings ##STR00001##
A catalyst system can include the metallocene compound, a non-coordinating anion type activator comprising a supported alumoxane or aluminum alkyl, and optionally a scavenger. A process for making a polymeric product can comprise: contacting a C2-C22 alpha-olefin feed with the catalyst system to obtain a polymerization reaction mixture; and obtaining a polymer product from the polymerization reaction mixture. A polymer product can be made by the process to exhibit at least an Mn from 7000 g/mol to 70000 g/mol and a PDI from 4.1 to 9.0.

A supported catalyst including a novel metallocene compound having excellent polymerization activity, and a method for producing polypropylene by polymerizing propylene in the presence of the catalyst are provided. The metallocene-supported catalyst of the present invention can produce a polypropylene having a relatively narrow molecular weight distribution and a SPAN value.

A catalyst composition and a method for preparing an olefin polymer by using the same are provided herein. In some embodiments, a catalyst composition includes a transition metal compound having a compound (A) represented by Chemical Formula 1 and a compound (B) represented by Chemical Formula 2 present in a molar ratio of 1.6:1 to 18. The catalyst composition has high activity in an olefin polymerization reaction and can contribute to a reduction of catalyst cost. The catalyst composition aides in high copolymerizability of olefin monomers, and the produced olefin polymers can exhibit excellent processability and long-term physical properties, suitable for a pipe.

This application relates to copolymer compositions and copolymerization processes. The processes may use two different metallocene catalysts: one capable of producing high molecular weight copolymers; and one suitable for producing lower molecular weight copolymers having at least a portion of vinyl terminations, and the copolymer compositions produced thereby. Copolymer compositions may comprise (1) a first ethylene copolymer fraction having high molecular weight, exhibiting branching topology, and having relatively lower ethylene content (based on the weight of the first ethylene copolymer fraction); and (2) a second ethylene copolymer fraction having low molecular weight, exhibiting linear rheology, and having relatively higher ethylene content (based on the weight of the second ethylene copolymer fraction). It is believed that the unique combination of these properties provides a copolymer composition with advantageous viscosity modifying properties, such as an excellent combination of shear thinning and fuel economy, as well as high thickening efficiency.

An elastomeric article comprising an olefin-block copolymer comprising within a range from 4 to 40 mol % of C4 to C12 -olefin derived units, the remainder being ethylene-derived units, wherein the melting point temperature (T.sub.m2) is within a range from 92 C. to 120 C., and having an M.sub.w/M.sub.n value of less than 2.5. The olefin-block copolymer is desirably generated by combining ethylene, C4 to C12 -olefins, a single site catalyst, preferably a fluxional catalyst, and an activator. The elastomeric article may be an elastic hygiene garment, especially a garment comprising a waistband, stretch ear panels and/or belly bands.